NELSON FLOODS AND MUDSLIDES December 23, 2011Posted by wmmbb in Environment, greenhouse emissions, Natural Environment.
The rainstorm that last week hit the New Zealand city of Nelson, the 9th largest urban area in the country, was the heaviest ever to hit such a populated area. Civil Defence operations controller, Jim Frater, was quoted in the Nelson Mail as saying:
”This is not just exceptional – this has never happened before”.
Here is some video footage:
So the question then is, was this due to climate change? Sarah Young in the Nelson Mail reports:
Nelson’s recent flooding is in line with climate change projections and what we can expect more of in the future, says a Nelson expert on climate change.
Carbon Farm director Murray McClintock said that what people had seen in the region’s recent deluge was exactly what an Intergovernmental Panel on Climate Change (IPCC) report released last month was predicting.
The IPCC report said the frequency of heavy precipitation, or the proportion of total rainfall from heavy falls, would increase in the 21st century over many areas, meaning that cloudbursts which could have been expected once in 20 years would now become one-in-five-year occurrences.
Dr McClintock said warming temperatures contributed to more water vapour in the atmosphere, leading to a lot more rain.
Projections of more intense rain were being borne out locally, with two significant high-intensity rain flooding events in the region in as many years, he said.
Both last week’s flood, and the flooding of the Aorere and Anatoki rivers in Golden Bay in December last year, were classified as one-in-50-year events.
However, the difficulty was saying with any certainty whether this was linked to climate change, Dr McClintock said.
“Some people will say there’s no basis for that certainty, but we have got to be realistic. We have projections that’s what’s going to happen, and it is happening, so it’s just as foolish to say it’s not climate change.
“It’s not one-off events – it’s starting to look like a trend.”
Such events were leading to “intense competition for resources and political attention”.
However, the necessary focus on recovery and spending more money on fixing infrastructure – a big strain on budgets in tight economic times – meant there was less money for combating climate change, he said.
It also meant an adaptive approach was taking precedence over a mitigative one, which was not ideal, considering that the cost of cleaning up was bigger than the cost of prevention, he said.
The Stern Review on the Economics of Climate Change, a report for the British Government released in 2006, estimated that capping climate change would cost about 1 per cent of global GDP, while letting things go on and dealing with the impacts would cost between 5 and 20 per cent.
In Nelson, people were going to have to put more energy into planning for things like how to cope with rising sea levels, more frequent storms and protecting freshwater aquifers from seawater pollution, Dr McClintock said.
Agriculture would bear the brunt of significant flood events, with stock and production levels affected, as well as blocked roads stopping perishable products getting to market, and some farm properties would face years of cleaning up, he said.
Weather events have compound effects, especially when they have not been foreseen and have not been engineered for. Some choose to deny that climate change is happening, and this is not the only event of its kind in the past year but is a case study of the consequences. If the Stern report is even half right about the economic consequences of global warming and stimulus for pre-emptive action, which becomes less effective the longer it is delayed.
The Nelson Mail has a report written by Martin Doyle explaining the big storm – global warming has not a factor, it was just one of the freak events that strangely are happening with increasing frequency around the world.